Remodelling of the palatal dome following rapid maxillary expansion (RME): laser scan-quantifications during a low growth period.

Muchitsch A. P., Winsauer H., Wendl B., Pichelmayer M., Kuljuh E., Szalay A., Muchitsch M. Remodelling of the palatal dome following rapid maxillary expansion (RME): laser scan-quantifications during a low growth period. Orthod Craniofac Res 2012;15:30–38 © John Wiley & Sons A/S Structured Abstract Objectives –  To evaluate changes in the palatal vault after rapid maxillary expansion (RME) with bonded splint appliances. Setting and Sample Population –  The sample comprised 24 children (12 boys and 12 girls) with mixed dentition (mean age 8.3 years; range 6.4–10.4 years). Materials and Methods –  Following expansion, the splint appliance was used as a retainer for 6 months and then removed. Study casts were taken before RME (T0) and when the appliance was removed (T1). Then, 3D laser scans were taken to build complete 3D jaw models. Frontal cross sections were constructed at 53–63, 55–65 and 16–26, exported as coordinates, and finite element calculated to quantify their area, width and height. Maxillary length was also determined. Results –  Paired t-tests indicated statistically significant increases in the average palatal width (T1–T0 = 6.53–6.79 mm) and cross-sectional area (T1–T0 = 20.39–21.39 mm2) after RME (p   0.99 (p < 0.001) for all tested parameters. Conclusions –  Rapid maxillary expansion distinctly increased mean palatal widths and cross-sectional areas. However, palatal height (55–65) and maxillary length decreased to a small extent.